#include <bits/stdc++.h>
using namespace std;

int main() {
  string s;
  cin >> s;
  map<string, string> h;
  h["red"] = "SSS";
  h["blue"] = "FFF";
  h["green"] = "MMM";
  if (h.count(s)) {
    cout << h[s];
  } else {
    cout << "Unknown";
  }

  return 0;
}
